So, as I understand your facts, the only “biometric data” involved here is your daughter’s fingerprint, which is then used as a key to open the register. No federal or Michigan law requires that the business get your consent before your daughter provides the finger print for use in their cash register system.

I’m also a little baffled as to what risks you fear from the business having that information. It already presumably has her name, address, SSN, and birth date, and far more damage could be done with that data than with her fingerprint.

Even if the potential risk is 0.000000000000001%? That would be a little silly, don't you think? Why do you think there is more risk involved with your daughter's "biometric data" than, for example, her social security number, which the employer must necessarily have?